At the moment, there is no "logging in" to TM, because users cannot store anything on the TM site directly. This works well for much of what we do now. The current user and current units selection are stored only in browser cookies. I have been hesitant (ok, I've outright refused) to add any sort of login capability that would allow user-based preferences to be stored. TM's database is not writable from the web front end and I intend to keep it that way to avoid potential security problems. Basically, I don't want to deal with a breakin, and I don't want TM to lose its happy home in a machine room with conditioned power and an essentially unlimited pipe to the Internet.
However, user-based preferences would be nice. One idea that's been coming up elsewhere in the forum is to have a user decide how to view stats and maps. This could be as simple as color and font preferences, or more interesting like restricting which regions and/or systems to include on maps and stats.
So my question, does anyone have experience adding one of those "Log in with Google" buttons and using people's Google accounts to store information for a third-party such as TM? It seems these are done most commonly with Google and Facebook, but I think I've also seen GitHub and Microsoft, and I'm sure there are others.
